1918, Irises, the Reticulata Section by Dykes

VISITORS to my garden often ask what first induced me to take up the cultivation of Irises, and my answer is that it was the desire to grow something which from the open ground would give me flowers in those winter months when most small gardens are entirely devoid of flowers of any kind. The first flowers of my first reticulates proved so fascinating that, once I had seen them open in my garden, 1 was eager to go on growing all obtainable Irises, raising seedlings of them and hybrids between them. It is seldom now that a week passes in any year, except, indeed, during unbroken spells of frost and snow, without some Iris buds appearing. The well-known Algerian I. unguicularis (syn. stylosa) is a great stand-by in the darkest days of winter, especially when the clumps have become well established in some warm, sunny corner against a wall, where slugs and snails are not too numerous and the soil is light and poor; but, once we have reached the New Year, it is seldom long before the first buds of some reticulata Iris emerge from their sheaths.

The name reticulata was given to draw attention to the fact that the outer coat of the bulbs consists of a network of fibres. All the members of the section are found in the region lying between the Caucasus and the Dead Sea on the North and South, and Western Asia Minor and Mesopotamia to the West and East, for I. Kolpakowskiana and I. Winkleri are so imperfectly known that their position in the genus is still a matter of conjecture.

The first to appear is usually I. histrioides, which in its best form from the neighbourhood of Amasia in Northern Asia Minor produces a magnificent flower quite 5 inches across. The colour is a bright rich blue, with a certain amount of white groundwork appearing in small patches on the blade of the falls. The flowers appear with extraordinary rapidity when a few warm days follow a period of frost and snow, and shoot up so rapidly that they outdistance the points of the stout, four-sided leaves. Of this Iris there is an inferior form, called sophenensis, from the ancient name of the district from which it comes. Its colour is inclined to be a rather dull blue of a slaty shade, and the plant is smaller in all its parts and in every way less desirable than the type.

Further south in Asia Minor we get I. histrio, so named because its livery was thought to be as gaudy as that of an actor. The colour varies a good deal, but nearly always consists, on the falls, of a mottled effect produced by spots and blotches of two shades of blue purple. I. histrio is at once more slender and, in my experience, more delicate than I. histrioides, though some of its forms are very beautiful. The most remarkable was sent to me from Marash, and had flowers which were wholly of a dark reddish black. For some years it led a precarious existence here, but now I am afraid the last bulb has succumbed. Possibly in other English gardens the bulbs might have been more vigorous, for I am inclined to think that Asia Minor plants are, as a whole, peculiarly unsuited to light sandy soils. Chionodoxa is a pleasing exception, but it may well be that its home is on some comparatively rare geological formation and not on that heavy red clay soil which is so often found in limestone districts in Southern Europe and apparently in Asia Minor, and which seems to contain some plant food that cannot be artificially supplied with any certainty. The yellow I. Danfordia; is another example of this difiiculty. After a bulb has flowered, it does not seem to form a few bulbs of which one or two will flower the next year and the rest the year after, but a vast number of bulblets no bigger than a grain of Wheat, which I find it difiicult in this poor soil to nurse on till they become strong enough to flower.

Reticulata itself is easier to manage and increases rapidly unless the bulbs fall victims to the fell disease, which sometimes carries off whole colonie's. The remedy seems to be to lift the bulbs annually and to replant them again shortly afterwards in fresh soil. The bulbs should be carefully picked over while they are out of the ground, and any " suspects " burnt.

One of the puzzles about I. reticulata is how the well-known deep blue form ever came to be known as the type. All the wild examples that have ever reached me from its home in the Caucasus have been of the red purple shade that is claimed for Krelagei, and Bieberstein's original illustration (M. Bieberstein, " Cent. Plant. Rar. Taur. Cauc," I., t. II [1810]) is apparently neither the one nor the other, but a paler blue fonu more like that which Mr. Bowles discovered in his garden and christened Cantab. The latter now rejoices, I believe, in a first-class certificate, though I must confess to being surprised when 1 read that it had attained to that honour. It is undoubtedly distinct and of good constitution for a reticulata, but it always seems to me that plants that lend themselves to being grown in a mass in pots or pans fare much better at the hands of the Floral Committee than do others which are only at their best in the garden. I may be prejudiced, but it does seem to me that there are a good many more strikingly handsome and more easily grown garden Irises than Cantab, though the latter may be more readily conveyed to a show in good condition.

Another puzzle connected with I. reticulate is that seedlings of the blue type always, in my experience, give red purple forms. It is only in the second generation, produced by cross-fertilizing the red purple seedlings among themselves, that blue purple forms like the so-called type appear. This result does not seem to tally with the Mendelian laws, for whether the red colour were dominant over the blue or the blue over the red, by no known law would the self-fertilised blue give all reds in the first generation.

Perhaps the most difficult of all the reticulates to grow is I. Vartani, from the neighbourhood of Nazareth. It is distinguished by the long style crests and by its strong scent of Almonds. The colour is usually a pale slaty blue, though a few years ago there was obtainable a white form, of which some were beautifully mottled with pale blue. I. Vartani was valuable because freshly imported bulbs could be relied upon to flower by Christmas, if not earlier. Let us hope that we shall be able to import it again before long.

Anyone who delights in brilliancy of colouring and in velvety texture of petal, rather than in the size of the flowers, should obtain a few bulbs of L bakeriana and make crosses between this Mesopotamian species and the best forms of reticulata and Krelagei. The deep velvety lip of Bakeriana seems always to be present in the hybrids, and this species, which has no yellow in its flowers, seems also able to suppress the orange central line of reticulata. Many years ago now Max Leichtlin sent me a present of a single bulb labelled Bakeriana Melaina. When it flowered I suspected this "black" Bakeriana of being a hybrid of Bakeriana and reticulata, and determined to try the cross. Two or three years ago the descendants of Leichtlin's bulb and the first of my hybrids opened on the same day and were identical.

There has been much variety among these hybrids, some of which I hope to be able to keep and grow on, but some of which I have lost through careless treatment, owing to lack of labour in these hard times.

It would be interesting to see what the result of hybridising I. Danfordia' with any other reticulata would be. Would the yellow colour be altogether obscured, and would the minute bristle-like standards become lengthened and more obvious? No hybrid of this Iris is, however, known at present.

Seeds of the reticulatas should be sown early in the autumn in fairly deep pots of rich soil. The pots should be left in the open until the seeds germinate early in the new year. Then the protection of a cold frame will do them no harm, and they may be left there to become quite dry in summer. Later on they should, be put out in the open again in the same pots for the winter. At the end of their second season they may be sifted out of the pots and planted out in nursery beds, where they will flower a year or two later. All the species and forms look best when growing either in the rock garden or among dwarf shrubs at the edge of a shrubbery. The type especially goes well with Chionodoxa sardensis, and I advise anyone who has not seen them together to try the effect.

Iris reticulata is often said to be capricious. Perhaps it is, but the truth seems rather to be that it suffers from having to make its growth amid the frequent changes of temperature, which render the early months of the year so trying in England. The best we can do is to make the bulbs strong by good feeding, and this is more easily and safely done by planting them in soil that is naturally rich in plant food than by trying to enrich poor soil at the planting-time by a liberal addition of half-decayed leaf-mould or manure. Both of these are only too apt to foster the fungoid, growths to which the bulbs are such easy victims. The bulbs should be lifted as soon as the foliage has turned yellow, and it may sometimes be useful to know that little harm is done to them if it is necessary to shift them when they are actually in flower.

Charterhouse, Godalming. W. R. Dykes.

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